Kara DioGuardi

Kara DioGuardi is a singer-songwriter, record producer, music publisher, A&R executive, and TV personality. And as of 2009, she was added as a fourth judge on American Idol.

DioGuardi voiced herself alongside Idol host Ryan Seacrest, and fellow judges Randy Jackson, Ellen DeGeneres, and Simon Cowell.

Guest stars in season 21

Seth Rogen • Kevin Michael Richardson • Matt Groening • Chuck Liddell • Jonah Hill • Neve Campbell • Smothers Brothers (Dick Smothers • Tom Smothers) • Peyton Manning • Eli Manning • Cooper Manning • Kim Cattrall • Huell Howser • Jordan Nagai • Mitch Albom • Anne Hathaway • Gary Larson • Eartha Kitt • Jackie Mason • Chris Martin • Bob Costas • Wren T. Brown • Sarah Silverman • Angela Bassett • Sacha Baron Cohen • Yael Naim • Joe Mantegna • Jane Kaczmarek • Maurice LaMarche • Eddie Izzard • Don Pardo • Kelsey Grammer • Ryan Seacrest • Randy Jackson • Ellen DeGeneres • Kara DioGuardi • Simon Cowell • Rupert Murdoch